Becker's Muscular Dystrophy

Hello -

I am being tested to see if I have the dystrophin gene because my male cousin has Becker's muscular dystrophy. My doctor thinks I might be a carrier with mild symptoms.  However, my cousin in my father's brother's son.  My understanding is that Becker's comes from the mother's gene. I am not a blood relative of my cousin's mother.  Is there any way I could have inherited this from my father's side of the family?  After reading up on this, I'm puzzled as to why I am being tested for it and wonder if the doctor misunderstood the family relation.

Thank you.

[Fernando Roque, MD]

Hi. Becker's muscular dystrophy is an X-linked recessive inherited disorder.  Males who manifest the disorder would get their X chromosome from their mother, so you're right in saying it comes from the mother's gene in your cousin's case.  For females to manifest the disease, both the father and the mother must have the genes for the disease. So you're also right in saying that you couldn't have inherited it from your father's side of the family, unless your father himself has it.  Maybe your doctor got confused about your family relation.